batgrbproduct Analysis for Trigger=221755
Analysis Summary
Notes:
- 1) No attempt has been made to eliminate the non-significant decimal places.
- 2) This batgrbproduct analysis is done of the amount of data for this trigger downloaded to date.
- 3) This page will be updated for up to 8 downlinks after the trigger.
======================================================================
BAT GRB EVENT DATA PROCESSING REPORT
Process Script Ver: batgrbproduct v2.41
Process Start Time (local time): Tue Jan 1 21:54:06 EST 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger221755/SDC
======================================================================
Trigger: 00221755 Segment: 000
BAT Trigger Time: 175893150.592 [s; MET]
Trigger Stop: 175893154.688 [s; MET]
UTC: 2006-07-29T19:12:29.244420 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 95.3382279470773 Dec: -62.3451070936891 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.13
Image Trigger?: NO
Rate S/N Ratio: 8.36660026534076 [ if not an image trigger ]
Image S/N Ratio: 7.13
Flight Position: [ source = BAT ]
RA: 95.3382279470773 Dec: -62.3451070936891 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 95.2788844739047 Dec: -62.2274535717144 [deg; J2000]
{ 06h 21m 06.9s , -62d 13' 38.8" }
+/- 4.41315050411803 [arcmin] (estimated 90% radius based on SNR)
+/- 3.26248099353937 [arcmin] (formal 1-sigma fit error)
SNR: 3.64794895993925
RA = 6h 21m 6.9s (95.278884 deg.)
Dec = -62d 13' 39" (-62.227454 deg.)
Angular difference between Flight and Ground position is 7.250819 arcmin
Partial Coding Fraction: 0.1875 [ including projection effects ]
Duration
T90: 115.348000019789 +/- 33.90346061055
Measured from: 3.15199998021126
to: 118.5 [s; relative to TRIGTIME]
T50: 21.7120000123978 +/- 2.97245486925609
Measured from: 73.6439999938011
to: 95.3560000061989 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 91.9679999947548
to: 92.9679999947548 [s; relative to TRIGTIME]
Total Fluence
Measured from: 0.912000000476837
to: 131.739999979734 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 1.478401 1.718619 1.011202 0.296754
0.099422 0.100761 0.091017 0.085834 [error]
Peak 0.051945 0.054039 0.030711 0.009651
0.005205 0.005317 0.004551 0.004051 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
=== Fluence/Peak Flux Summary ===
Model Band1 Band2 Band3 Band4 Band5 Total
15-25 25-50 50-100 100-350 15-150 15-350 keV
Fluence Power-law 5.46e-07 7.99e-07 8.70e-07 1.77e-06 2.76e-06 3.98e-06 erg/cm2
Error 6.35e-08 5.64e-08 9.30e-08 3.99e-07 2.14e-07 4.78e-07 erg/cm2
Peak flux Power-law 6.59e-01 4.66e-01 2.17e-01 1.41e-01 1.41e+00 1.48e+00 ph/cm2/s
Error 1.07e-01 5.03e-02 3.94e-02 4.93e-02 1.55e-01 1.60e-01 ph/cm2/s
Fluence Cutoff-PL 5.46e-07 8.00e-07 8.70e-07 1.76e-06 2.76e-06 3.96e-06 erg/cm2
Error 6.35e-08 5.64e-08 9.30e-08 3.96e-07 2.14e-07 4.76e-07 erg/cm2
Peak flux Cutoff-PL 6.54e-01 4.70e-01 2.17e-01 1.27e-01 1.41e+00 1.47e+00 ph/cm2/s
Error 1.14e-01 5.07e-02 3.99e-02 7.57e-02 1.58e-01 1.80e-01 ph/cm2/s
Fluence Band 5.27e-07 8.13e-07 8.61e-07 1.64e-06 2.73e-06 3.85e-06 erg/cm2
Error 9.16e-08 7.42e-08 9.57e-08 7.91e-07 2.34e-07 5.09e-07 erg/cm2
Peak flux Band 6.54e-01 4.70e-01 2.17e-01 1.26e-01 1.41e+00 1.47e+00 ph/cm2/s
Error 1.14e-01 5.97e-02 4.03e-02 9.73e-02 1.19e-01 1.81e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.877 0.135 - - 2.29e-03 1.78e-04 47.634 57
CPL 1.784 0.536 109.4 0.0 2.56e-03 1.19e-03 47.714 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.103 0.211 - - 8.95e-03 1.22e-03 53.644 57
CPL 1.968 0.000 10.7 4999.8 1.06e-02 3.56e-03 53.627 0
Model : spectral model: simple power-law (PL) and cutoff power-law (CPL)
Ph_index : photon index: E^-{Ph_index} (minus sign is not included in the index)
Ph_90err : 90% error of the photon index
Epeak : Epeak in keV
Epeak_90err: 90% error of Epeak
Norm : normalization at 50 keV in PL model and at 1 keV in CPL model
Nomr_90err : 90% error of the normalization
chi2 : Chi-Squared
dof : degree of freedom
=== T90/T50 calculation in the 50-300 keV band (BATSE band) using 64 ms lc ===
T90 in the 50-300 keV band: 41.280000 sec.
T50 in the 50-300 keV band: 15.808000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 130.828 0.912 131.740
T90 115.348 3.152 118.500
T50 21.712 73.644 95.356
Peak 1.000 91.968 92.968
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
95.2789 -62.2275 0.0527 42.9 -52.4 0.6958 3.6 TRIG_00221755
------------------------------------------
Foreground time interval of the image:
0.912 57.413 (delta_t = 56.501 [sec])
Background time interval of the image:
-239.592 0.912 (delta_t = 240.504 [sec])
Lightcurves
Notes:
- 1) All plots contain as much data as has been downloaded to date.
- 2) Multiple plots of different time binning/intervals are shown to cover all scenarios of short/long GRBs, rate/image triggers, and real/false positives.
- 3) For all the mask-weighted lightcurves, the y-axis units are counts/sec/det where a det is 0.4 x 0.4 = 0.16 sq cm.
- 4) The verticle lines correspond to following: green dotted lines are T50 interval, black dotted lines are T90 interval, blue solid line(s) is a spacecraft slew start time, and orange solid line(s) is a spacecraft slew end time.
- 5) Time of each bin is in the middle of the bin.
1 s binning
From T0-310 s to T0+310 s
From T100_start - 20 s to T100_end + 30 s
Full time interval
64 ms binning
Full time interval
From T100_start to T100_end
From T0-5 sec to T0+5 sec
16 ms binning
From T100_start-5 s to T100_start+5 s
8 ms binning
From T100_start-3 s to T100_start+3 s
2 ms binning
From T100_start-1 s to T100_start+1 s
SN=5 or 10 sec. binning (whichever binning is satisfied first)
SN=5 or 10 sec. binning (T < 200 sec)
Spectra
Notes:
- 1) The fitting includes the systematic errors.
- 2) For long bursts, a spectral fit of the pre-slew DRM will introduce some errors in both a spectral shape and a normalization if the PHA file contains a lot of the slew/post-slew time interval.
- 3) For fits to more complicated models (e.g. a power-law over a cutoff power-law), the BAT team has decided to require a chi-square improvement of more than 6 for each extra dof.
Time averaged spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.912 sec. to 131.740 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.87705 ( -0.133310 0.136137 )
Norm@50keV : 2.294717E-03 ( -1.789052E-04 1.766582E-04) )
------------------------------------------------------------
Chi-Squared = 47.63448 using 59 PHA bins.
Reduced chi-squared = 0.8356927 for 57 degrees of freedom
Null hypothesis probability = 0.807
Photon flux (15-150 keV) in 130.8 sec: 0.326153 ( -0.023756 0.023844 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.7595e-06 ( -2.13322e-07 2.14394e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.912 sec. to 131.740 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.78369 ( -0.474109 0.598749 )
Epeak [keV] : 109.404 ( )
Norm@50keV : 2.560542E-03 ( -2.195982E-04 2.164532E-03) )
------------------------------------------------------------
Chi-Squared = 47.71424 using 59 PHA bins.
but latest trial 2.02082 gives Chi-Squared = 0.118752
Reduced chi-squared = 0.8520401 for 56 degrees of freedom
Null hypothesis probability = 0.777
Photon flux (15-150 keV) in 130.8 sec: 0.326022 ( -0.023746 0.023834 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.75923e-06 ( -2.12929e-07 2.14878e-07 ) ergs/cm2
Band function
Time interval is from 0.912 sec. to 131.740 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.35137 ( -8.64863 3.51998 )
beta : -1.91481 ( -8.08519 0.165351 )
Epeak [keV] : 37.4191 ( -37.3191 9962.58 )
Norm@50keV : 5.170814E-03 ( -5.170813E-03 331.425 )
------------------------------------------------------------
Chi-Squared = 47.43288 using 59 PHA bins.
Reduced chi-squared = 0.8624160 for 55 degrees of freedom
Null hypothesis probability = 0.756
Photon flux (15-150 keV) in 130.8 sec: 0.324182 ( -0.026654 0.024388 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.72762e-06 ( -2.35139e-07 2.32981e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 91.968 sec. to 92.968 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.10290 ( -0.204860 0.216609 )
Norm@50keV : 8.948262E-03 ( -1.239852E-03 1.202410E-03) )
------------------------------------------------------------
Chi-Squared = 53.64400 using 59 PHA bins.
Reduced chi-squared = 0.9411228 for 57 degrees of freedom
Null hypothesis probability = 0.602
Photon flux (15-150 keV) in 1.000 sec: 1.40981 ( -0.15489 0.15511 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.31661e-08 ( -1.0307e-08 1.04611e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 91.968 sec. to 92.968 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.96801 ( )
Epeak [keV] : 10.6759 ( -0.855791 9998.76 )
Norm@50keV : 1.063028E-02 ( -4.890452E-03 2.226377E-03) )
------------------------------------------------------------
Chi-Squared = 53.62749 using 59 PHA bins.
but latest trial 1.248441E-02 gives Chi-Squared = 2.81191
Reduced chi-squared = 0.9576339 for 56 degrees of freedom
Null hypothesis probability = 0.565
Photon flux (15-150 keV) in 1.000 sec: 1.40591 ( -0.15831 0.15728 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.26381e-08 ( -9.7209e-09 1.0684e-08 ) ergs/cm2
Band function
Time interval is from 91.968 sec. to 92.968 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.97599 ( -8.17743 6.82257 )
beta : -3.76605 ( -0.391777 0.205656 )
Epeak [keV] : 10.6988 ( -10.6217 9989.28 )
Norm@50keV : 1.030126E-02 ( -8.013675E-02 2200.99 )
------------------------------------------------------------
Chi-Squared = 53.66665 using 59 PHA bins.
Reduced chi-squared = 0.9757572 for 55 degrees of freedom
Null hypothesis probability = 0.526
Photon flux (15-150 keV) in 1.000 sec: 1.40585 ( -0.15851 0.07959 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.04186e-07 ( -1.81627e-08 1.79793e-07 ) ergs/cm2
Plot creation:
Tue Jan 1 22:15:28 EST 2008